Optical networks may transfer data over light waves. For example, a particular light wave may be generated at an optical transmitter and forwarded over an optical network to an optical receiver. Using an optical protocol, various light waves may be multiplexed using different frequency channels for transmission through the same transmission medium to various optical receivers. At the optical receivers, the light waves may be decoded into electrical signals.
An optical receiver may receive signals via an amplifier circuit that includes an integrated automatic gain control (AGC) loop. Automatic gain control is used in a receiver to vary gain in order to (1) maintain a constant output signal amplitude and (2) increase the dynamic range of the receiver. One approach to setting the loop bandwidth may be by using either an integrated or an external capacitance. Another approach may be implemented with a digital AGC loop that discovers and controls the AGC bandwidth.